 The Secret of Shark Reef by William Arden |  The Secret of the Crooked Cat by William Arden |  The Secret of the Haunted Mirror by M. V. Carey |  The Secret of Skeleton Island by Robert Arthur |  The Case of the Bizarre Bouquets by Nancy Springer |  The Mysterious Visitor by Julie Campbell |  Mandie and the Cherokee Legend by Lois Gladys Leppard |  Mandie and the Abandoned Mine by Lois Gladys Leppard |  Mandie and the Secret Tunnel by Lois Gladys Leppard |  Capture the Flag by Kate Messner |  The Sinister Signpost by Franklin W. Dixon |  The Mark on the Door by Franklin W. Dixon |  The Haunted Fort by Franklin W. Dixon |  Three Cheers Secret Seven by Enid Blyton |  Look Out Secret Seven by Enid Blyton |  The Secret of Skull Mountain by Franklin W. Dixon |  The Flickering Torch Mystery by Franklin W. Dixon |  The Secret of Wildcat Swamp by Franklin W. Dixon |  The Secret Warning by Franklin W. Dixon |  The Secret Panel by Franklin W. Dixon |